Sunday, August 4, 2013

The Dragons of Summer

The male White-faced Meadowhawk

The Turtle Pond is home to many dragonflies this summer
This summer the number of dragonflies at the turtle pond is way up. Perhaps the season’s record rainfall is responsible for the population growth. Certainly there has been a net increase in wetlands for insects to breed in. Even vernal ponds have retained high water levels long into the summer. Mosquitoes and other small flying insects provide the adult dragonflies with much of their food, and definitely there has been a net increase in those pesky creatures this summer.

An adult male Widow Skimmer has a highly recognizable wing pattern
The male 12-spotted Skimmer - another easily recognizable species
At the turtle pond on a hot afternoon, the diversity of dragonflies is quite incredible. Around a dozen species were represented around one section of the shore. Mostly these were males, patrolling their territories and simultaneously searching for females to mate with.
Clashes between males of the same species were common, and they consisted of the rivals giving chase and then making very audible wing to wing contact. This warfare doesn't seem to result in any damage to the combatants and often the very same individuals will continue to duke it out off and on for hours at a time and even for many consecutive days.
The male Eastern Pondhawk at rest on his highly contested territory
The female Eastern Pondhawk
Egg laying is also taking place on the pond. The females of different dragonfly species have different techniques of laying, but all of them lay directly into the water. The female Common Whitetail hovers low over one spot and repeatedly, rhythmically dips the tip of her abdomen into the water, laying egg after egg. While she lays, a male Common Whitetail hovers just above her and occasionally flies down to make brief contact. I also watched The female Green Darner laying eggs; she did this while perched on a piece of floating vegetation.The male was clasping her neck as she deposited her eggs into the water.
The female Green Darner Lays eggs while the male clasps her by the neck
A female Spatterdock Darner attaches eggs to a submerged cattail stem
On cattails and other emergent vegetation, the empty exoskeletons of dragonfly nymphs remain hanging on to the leaves where they were shed. The nymph lived a relatively long life as a fierce underwater predator - consuming a wide variety of underwater creatures. 

The shed exoskeleton of a dragonfly nymph hangs onto a cattail leaf
My goal of getting pictures of each species at the pond proved too difficult. The fact is that some species rarely ever seemed to land. I watched the male Black Saddlebags Dragonfly chasing away rivals, mating, and clasping his mate while she laid eggs on the wing, but I could never find one perched. Surely, they have to rest at some point! I could only think that they prefer to perch in a secluded place - possibly in the tall reeds.
The male Common Whitetail perches in a prominent place right above the water
White-faced Meadowhawks mating - note the female's lighter color
The Eastern Amberwing is a small but beautiful species 
Some of my favorite dragonflies are the smaller species like the meadowhawks and pondhawks. The Eastern Amberwing is also quite small - only about half the size of a Green Darner. Its wings are amber colored and its abdomen is orange with white segment bands.

The male Calico Pennant is hard to mistake with its red wing markings
Dragonflies are fearsome predators but they are by no means at the top of the foodchain. They are the preferred food of some birds – chiefly flycatchers like the Eastern Kingbird. Occasionally I come upon discarded dragonfly wings on the trail – that’s a sign that the flycatchers have been busy.
The Eastern Kingbird is a well known dragon slayer

Unicorn Clubtail - note the black club at the end of abdomen & aqua eyes
Blue Damselflies (not a dragonfly species) also mate at the Turtle Pond

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